Where the examining or opposition division holds hearings for the purpose of taking evidence (see E‑IV, 1.3) or if the case in question is expected to give rise to particular legal issues, it is advisable that the division be enlarged by the addition of a legally qualified examiner, if this is not already the case (see D‑II, 2.2).

The evidence of witnesses is normally taken at oral proceedings either on the premises of the EPO or by videoconferenc

The parties, witnesses and experts to be heard must be invited to appear to give evidence on the date fixed. The summons must be notified. At least two months' notice of a summons issued to a party, witness or expert to give evidence must be given, unless they agree to a shorter period.

The department responsible for the taking of evidence in the form of a hearing of witnesses, parties and experts will, in substantive examination and opposition proceedings, be the division before which the taking of evidence as part of oral proceedings would normally take place. If evidence is to be taken, the examining or opposition division will normally have been enlarged to include a legally qualified member. The division may commission one of its members to examine the evidence adduced.

Formal taking of evidence in accordance with Rule 117 will occur mainly in opposition proceedings and hardly ever before the examining division. The following sections of this chapter are therefore based primarily on opposition proceedings. However, they also apply mutatis mutandis to other proceedings and particularly to substantive examination.[Art. 117; Rule 117; ]

1. Taking of evidence by the departments of the EPO

2. Conservation of evidence

3. Taking of evidence by courts or authorities of the contracting states

4. Evaluation of evidence