A solenoid valve comprising: a valve sleeve including a spool arranged therein in a movable condition in the axial direction; a solenoid case connected to one end portion in the axial direction of said valve sleeve; a molded object mounted inside of said solenoid case and including a coil; a center post provided on the valve sleeve side of the inside of said molded object; a side ring provided on the opposite side from said valve sleeve of the inside of said molded object; and a plunger arranged in said side ring and said center post in a movable condition in the axial direction, said plunger being moved in the axial direction by magnetic force generated by said coil; characterized in that said solenoid valve further comprises; a breathing groove (29, 66) formed on any one or both of said center post and said spool, and forming a fluid passage communicating to a space on the spool side of said plunger when said spool is arranged closest to said plunger and a plunger side end portion of said spool and a spool side end portion of said center post come in contact with each other, a breathing hole formed at a solenoid case side end portion of said valve sleeve, to communicate said breathing groove (29, 66) to a void between an inner bottom face of said solenoid case and an outer bottom face of said molded object, breathing routes (231, 232) formed on an outer circumference of said molded object to communicate said void between the inner bottom face of said solenoid case and the outer bottom face of said molded object, to which said breathing hole communicates to a breathing window formed on said solenoid case and opening to outside, and grooves (371, 372, 373) formed on said side ring and said molded object to communicate an internal space of said side ring in which said plunger is arranged to a cutaway portion formed on said solenoid case to communicate to the outside. a valve sleeve including a spool arranged therein in a movable condition in the axial direction; a solenoid case connected to one end portion in the axial direction of said valve sleeve; a molded object mounted inside of said solenoid case and including a coil; a center post provided on the valve sleeve side of the inside of said molded object; a side ring provided on the opposite side from said valve sleeve of the inside of said molded object; and a plunger arranged in said side ring and said center post in a movable condition in the axial direction, said plunger being moved in the axial direction by magnetic force generated by said coil; characterized in that said solenoid valve further comprises; a breathing groove (29, 66) formed on any one or both of said center post and said spool, and forming a fluid passage communicating to a space on the spool side of said plunger when said spool is arranged closest to said plunger and a plunger side end portion of said spool and a spool side end portion of said center post come in contact with each other, a breathing hole formed at a solenoid case side end portion of said valve sleeve, to communicate said breathing groove (29, 66) to a void between an inner bottom face of said solenoid case and an outer bottom face of said molded object, breathing routes (231, 232) formed on an outer circumference of said molded object to communicate said void between the inner bottom face of said solenoid case and the outer bottom face of said molded object, to which said breathing hole communicates to a breathing window formed on said solenoid case and opening to outside, and grooves (371, 372, 373) formed on said side ring and said molded object to communicate an internal space of said side ring in which said plunger is arranged to a cutaway portion formed on said solenoid case to communicate to the outside.