This rigid electronic endoscope is formed of an endoscope body and an elongate tubular guide tube. An insertable part to be inserted through the guide tube is provided in front of this endoscope body. A solid state imaging device as an imaging means is provided in the tip part of this insertable part and a supporting part of a cross-sectional area smaller than of this tip part is provided in the rear of this tip part. A space as a treating tool inserting path or as a liquid feeding and sucking tube path which can feed and drain an irrigating liquid is formed between this supporting part and the inner surface of the guide tube.