To provide a porous panel member for a waterproof structure and the waterproof structure using this panel member, having heat insulating performance and stable waterproofness, easy in construction, and restraining cost.

A heat insulating layer 2 is formed by laying the porous panel members 20 and 21 having heat insulating performance and ventilatility on a processing object surface of a concrete skeleton 1. The porous panel members have porous parts 20a and 21a, and synthetic resin films 20b and 21b, and have step parts 20c and 21c thinly formed in the thickness in an end part. In laying, an anchor bolt 4 is driven in and fixed to a superposing part by superposing the step parts 20c and 21c. The layer thickness of the heat insulating layer 2 becomes substantially constant, and its upper surface becomes a flat surface of the synthetic resin films. A top coat 6 is applied by forming a waterproof layer 5 by covering its upper surface with a reactive elastic waterproof material.