An electromagnetic switch device for a starter, comprising: an electromagnetic switch which includes a pair of main fixed contacts, a main movable contact, and a main coil (25, 26), which opens and closes an electric circuit for a motor via the pair of main fixed contacts, and which engages a pinion with a ring gear via a shift lever when the main coil (25, 26) is energized; an auxiliary relay which includes a pair of sub fixed contacts, a sub movable contact, and a sub coil, the pair of sub fixed contacts being connected to the main coil (25, 26) of the electromagnetic switch, the auxiliary relay energizing the main coil (25, 26) of the electromagnetic switch via the pair of sub fixed contacts in response to a start signal; characterized in that it further comprises: a terminal block in which a main contact chamber that is open at the main coil side in an axial direction and in which the pair of main fixed contacts and the main movable contact are located, and the auxiliary relay that is open at a side opposite to the main coil side in the axial direction, are located adjacent to each other in the radial direction; and a cover provided at an opening side of the terminal block at which the auxiliary relay is located, the cover having through holes through which the main fixed contacts penetrate in a state where the auxiliary relay is sealed; and a sub contact spring, which is located between the cover and the sub movable contact of the auxiliary relay; and an elastic member which is located between the auxiliary relay and the cover, wherein the sub contact spring and the elastic member fix the auxiliary relay in the axial direction together with the terminal block and the cover. an electromagnetic switch which includes a pair of main fixed contacts, a main movable contact, and a main coil (25, 26), which opens and closes an electric circuit for a motor via the pair of main fixed contacts, and which engages a pinion with a ring gear via a shift lever when the main coil (25, 26) is energized; an auxiliary relay which includes a pair of sub fixed contacts, a sub movable contact, and a sub coil, the pair of sub fixed contacts being connected to the main coil (25, 26) of the electromagnetic switch, the auxiliary relay energizing the main coil (25, 26) of the electromagnetic switch via the pair of sub fixed contacts in response to a start signal; characterized in that it further comprises: a terminal block in which a main contact chamber that is open at the main coil side in an axial direction and in which the pair of main fixed contacts and the main movable contact are located, and the auxiliary relay that is open at a side opposite to the main coil side in the axial direction, are located adjacent to each other in the radial direction; and a cover provided at an opening side of the terminal block at which the auxiliary relay is located, the cover having through holes through which the main fixed contacts penetrate in a state where the auxiliary relay is sealed; and a sub contact spring, which is located between the cover and the sub movable contact of the auxiliary relay; and an elastic member which is located between the auxiliary relay and the cover, wherein the sub contact spring and the elastic member fix the auxiliary relay in the axial direction together with the terminal block and the cover. a terminal block in which a main contact chamber that is open at the main coil side in an axial direction and in which the pair of main fixed contacts and the main movable contact are located, and the auxiliary relay that is open at a side opposite to the main coil side in the axial direction, are located adjacent to each other in the radial direction; and a cover provided at an opening side of the terminal block at which the auxiliary relay is located, the cover having through holes through which the main fixed contacts penetrate in a state where the auxiliary relay is sealed; and a sub contact spring, which is located between the cover and the sub movable contact of the auxiliary relay; and an elastic member which is located between the auxiliary relay and the cover, wherein the sub contact spring and the elastic member fix the auxiliary relay in the axial direction together with the terminal block and the cover.