To provide a heat insulating cup made of paper, which consists of a paper cup main body and a paper cylindrical body, high in production efficiency, having adhesiveness and good in quality.

A body member forming the body part 11 of the paper cup main body comprises polyolefinic resin processed paper of which both inside and outside surfaces 2, 3 are coated with a polyolefinic resin film and the outside surface of the body part immediately under the mouth edge part 13 of the body part 11 of the paper cup main body is bonded and fixed to the outside surface of the curl part 21 in the paper cylindrical body through heat seal varnish 5.