To provide a diffuser for a fluid control valve capable of more surely suppressing or preventing generation of cavity and suppressing decrease of maximum flow rate and the fluid control valve.

The diffuser 31 for decreasing flowing speed of fluid 30 and converting kinetic energy into pressure is assembled in a downstream side opening part of a valve body 2. The diffuser 31 is formed in a hollow cone shape with an open bottom part 34, an inner angle (θ) of a top part 33 is 90° or smaller and a large number of small holes 32 are formed in a circumference wall.