ELECTRONICALLY CONTROLLED REGULATOR

An electronically controlled regulator capable of preventing occurrence of slow leakage via a pressure regulating valve when a valve is closed and avoiding fluctuation in discharge pressure caused by backlash provided in a valve shaft moving structure.In an electronically controlled regulator (1A) including a pressure regulating valve (20A) including a discharge pressure regulating unit that adjusts a pressure of a fluid by changing a distance between a valve body (22A) and a valve seat (23A) while reciprocating a valve shaft (21A) by a valve shaft moving structure using a feed screw (60), a piston (37A) that receives a fluid pressure in a discharge pressure chamber (3A) is slidably disposed, and a spring (70) that constantly biases the valve shaft (21A) in a valve closing direction is disposed.