Art. 128 EPC governs the inspection of European patent applications. Paragraphs 1, 2 and 5 regulate file inspection prior to publication of the application under Art. 93 EPC and are therefore exceptions, as an application must normally be kept secret until it is published. Thus file inspection may be granted under Art. 128(1) EPC if the applicant consents or under Art. 128(2) EPC if the applicant himself has invoked his rights under the application. Paragraphs Art. 128(3) EPC and Art. 128(4) EPC on the other hand regulate file inspection after the application has been published (see in this chapter III.M.1.2.).

According to J 5/81 (OJ 1982, 155), under Art. 128 EPC, the confidential treatment of patent applications ceases on publication of the application, not on expiry of the 18-month period mentioned in Art. 93(1) EPC. Any person who can prove that the applicant has invoked the rights under the European patent application against him may obtain inspection of the files before the publication of the application and without the consent of the applicant under Art. 128(2) EPC.

According to J 14/91 (OJ 1993, 479), rights under a European patent application could be considered invoked under Art. 128(2) EPC where their invocation was formulated in relation to the first filing in a contracting state but the subsequent European application was mentioned at the same time. Any dispute between the applicant and a third party concerning the latter's right to inspect the files pursuant to Art. 128(2) EPC was best decided in oral proceedings convened at short notice.

In J 27/87 the board confirmed the Receiving Section's decision to refuse a request pursuant to Art. 128(2) EPC, because there was no proof that the applicants had invoked their rights under the application against the appellants. The extracts from correspondence in which the applicants' representative asserted that his clients had developed a new technology and mentioned the patent application were not deemed sufficient evidence.

In the case before the board in T 1101/99, a formalities officer acting for the opposition division rejected the request for inspection of the file. The board noted that the term 'granting of inspection' set out in the Notice of the Vice-President of DG 2 of the EPO concerning the entrustment to formalities officers of certain duties normally the responsibility of the opposition divisions of the EPO (dated 28.4.1999, OJ 1999, 504, point 13) apparently referred only to a positive decision, whereas in the decision under appeal the request for inspection was rejected. The board found that there was no justification for interpreting the delegation of duties beyond its actual wording such that it would also cover the rejection of requests for file inspection.