A penetration structure for a fireproof compartment has a through hole(s) provided at a compartment and a pipe(s) penetrating through the through hole(s). A circumference of the pipe(s) is wound by an epoxy resin-containing thermally expandable resin composition sheet. The epoxy resin-containing thermally expandable resin composition sheet is a laminate of one or more epoxy resin-containing thermally expandable resin composition layers having at least one of linear grooves continuously formed and linear grooves intermittently formed, and two or more of the respective linear grooves being formed onto at least one surface of the epoxy resin-containing thermally expandable resin composition sheet with an interval, and one or more substrate layers. The epoxy-resin-containing thermally expandable resin composition sheet can be wound around the pipe by bending the sheet through use of the grooves even when the temperature is low.