A solenoid valve comprising: a main body part; a coil housed in said main body part; an armature adapted to be attracted by said coil; a valve part formed integral with said armature; and a valve seat which said valve part is adapted to rest on and move off; said valve seat being disposed between a high-pressure path and a low-pressure path; said valve part, when resting on said valve seat, disconnecting said high-pressure path and said low-pressure path from each other, said valve part, when moving off said valve seat, making said high-pressure path and said low-pressure path communicate with each other; a guided portion of said armature being formed by removing a portion of said armature through which a smaller amount of magnetic flux from said coil passes; a guide secured to said main body part engaging with said guided portion; and said guide supporting said armature in such a manner as to be movable between the rest position and the off-position; characterised by said armature comprising a magnetic portion made of a magnetic material and disposed at a location where the density of the magnetic flux generated by said coil is high, and a high-strength portion made of a high-strength material having a relatively high strength and disposed at a location where the density of the magnetic flux generated by said coil is low, said magnetic portion and said high-strength portion being secured to each other; said guided portion of said armature being formed in the shape of a through-hole in said high-strength portion; a plurality of said guided portions being formed through said armature, less than all of said guided portions engaging with said guide with the rest of said guided portions used as an oil releaser. a main body part; a coil housed in said main body part; an armature adapted to be attracted by said coil; a valve part formed integral with said armature; and a valve seat which said valve part is adapted to rest on and move off; said valve seat being disposed between a high-pressure path and a low-pressure path; said valve part, when resting on said valve seat, disconnecting said high-pressure path and said low-pressure path from each other, said valve part, when moving off said valve seat, making said high-pressure path and said low-pressure path communicate with each other; a guided portion of said armature being formed by removing a portion of said armature through which a smaller amount of magnetic flux from said coil passes; a guide secured to said main body part engaging with said guided portion; and said guide supporting said armature in such a manner as to be movable between the rest position and the off-position; characterised by said armature comprising a magnetic portion made of a magnetic material and disposed at a location where the density of the magnetic flux generated by said coil is high, and a high-strength portion made of a high-strength material having a relatively high strength and disposed at a location where the density of the magnetic flux generated by said coil is low, said magnetic portion and said high-strength portion being secured to each other; said guided portion of said armature being formed in the shape of a through-hole in said high-strength portion; a plurality of said guided portions being formed through said armature, less than all of said guided portions engaging with said guide with the rest of said guided portions used as an oil releaser.