Solar heat receiver and solar heat power generation device

A solar light heat receiver (5) comprises: a casing (10) having an opening (10a) which solar light enters; and a conduit system (20) provided in the casing and delivering a heat medium (A), which has been delivered from an outside fluid supply source, to an outside fluid supply destination after raising the temperature of the heat medium (A) by solar light. The conduit system (20) comprises: heat receiving pipes (21) housed within the casing and subjected to the solar light, which has entered from the opening of the casing, to raise the temperature of the heat medium flowing through the inside of the heat receiving pipes (21); an introduction header pipe (22) connected to the one end (21a) side of each of the heat receiving pipes and distributing the heat medium, which has been introduced from the fluid supply source, to the heat receiving pipes; and a delivery header pipe (23) which is connected to the other end side of each of the heat receiving pipes, collects the heat medium having passed through the heat receiving pipes, and delivers the heat medium to the fluid supply destination. The introduction header pipe and the delivery header pipe have a larger inner diameter than the heat receiving pipes (d