To carry out stable flow rate control by moderating flow rate change for a supply electric current.

A valve chest is airtightly partitioned into an upper part valve chest 5a and a lower part valve chest 5b by a plate spring 20 integrally installed on a plunger 7, the upper part valve chest 5a and the lower part valve chest 5b are constituted to communicate to each other only through a small diametrical resistance pipe 22 provided on the plate spring member 20, the upper part valve chest 5a is connected to a fluid inlet 2, the lower part valve chest 5b is connected to a fluid outlet 3 through a nozzle 4, and energizing force to press a sealing member 8 of the plunger 7 on the nozzle 4 by the plate spring 20 is given. Consequently, sudden change of the plunger 7 is restrained by using differential pressure of the upper part valve chest 5a and the lower part valve chest 5b.