A thermal overload relay, comprising within a case: a bimetal member which undergoes curving displacement due to heat generation caused by an overload current; a reversal mechanism (21, 35) which, when a displacement amount of the bimetal member exceeds a stipulated value, performs a reversal operation and switches a contact (38, 42); a columnar reset rod which is loaded into a shaft loading portion formed in the case so as to be freely pushed in, and one end of which engages with a movable portion of the reversal mechanism when pushed in; and a return spring, the spring force of which acts on the reset rod such that the other end of the reset rod protrudes from the case, the reset rod being configured to be switchable between a manual reset position in which the reversal mechanism is manually returned to an initial state prior to reversal by performing a push-in operation, and an automatic reset position in which the pushed-in state is held by a pushing and rotating operation from this manual reset position, and the reversal mechanism is automatically returned to the initial state, the thermal overload relay being characterized in that an axial runout restriction portion (51, 52, 47b), which restricts axial runout of the reset rod when the reset rod is held in the automatic reset position, is provided, wherein a bulging portion (51, 52) is formed in one among an outer periphery of the reset rod and an inner wall of the shaft loading portion, and when the reset rod is held in the automatic reset position, the bulging portion (51, 52) abuts the other among the outer periphery of the reset rod and the inner wall of the shaft loading portion, and a pressing force (F1, F3, F2) is generated between the reset rod and the shaft loading portion, thereby restricting axial runout of the reset rod. a bimetal member which undergoes curving displacement due to heat generation caused by an overload current; a reversal mechanism (21, 35) which, when a displacement amount of the bimetal member exceeds a stipulated value, performs a reversal operation and switches a contact (38, 42); a columnar reset rod which is loaded into a shaft loading portion formed in the case so as to be freely pushed in, and one end of which engages with a movable portion of the reversal mechanism when pushed in; and a return spring, the spring force of which acts on the reset rod such that the other end of the reset rod protrudes from the case, the reset rod being configured to be switchable between a manual reset position in which the reversal mechanism is manually returned to an initial state prior to reversal by performing a push-in operation, and an automatic reset position in which the pushed-in state is held by a pushing and rotating operation from this manual reset position, and the reversal mechanism is automatically returned to the initial state, the thermal overload relay being characterized in that an axial runout restriction portion (51, 52, 47b), which restricts axial runout of the reset rod when the reset rod is held in the automatic reset position, is provided, wherein a bulging portion (51, 52) is formed in one among an outer periphery of the reset rod and an inner wall of the shaft loading portion, and when the reset rod is held in the automatic reset position, the bulging portion (51, 52) abuts the other among the outer periphery of the reset rod and the inner wall of the shaft loading portion, and a pressing force (F1, F3, F2) is generated between the reset rod and the shaft loading portion, thereby restricting axial runout of the reset rod.