A pressure regulating valve includes a valve body with an input port, an output port and a drain port. A valve member is slidably arranged in the valve body for controlling the fluid communication among the ports and is positioned by an electromagnetic solenoid and a spring, both of which apply loads to the valve member. A spring load setting mechanism is used to move the valve member to a position at which a load according to an input signal to the electromagnetic solenoid, the load of the spring and a feedback pressure are balanced. A supply pressure fed to the input port is thereby regulated and output from the output port. The load setting mechanism includes a receiving plug screwed into the valve body for holding and supporting the spring in a compressed state and a retainer fixed on the valve body for holding the receiving plug against rotation. The receiving plug has an indexed portion at its distal end which is engaged by the restrainer for establishing a rotational position. One of the retainer and the indexed portion of the receiving plug has recesses whereas the other has protrusions for engaging the recesses.