There is provided a power supply apparatus for charging-type device including a transformer disposed in a main body of the power supply apparatus, current supply connection terminals connected to a secondary winding of the transformer, current receiving connection terminals so disposed in a charging-type device as to be capable of being coupled to and detached from the current supplying connection terminals, a storage battery so disposed in the charging-type device as to be charged from the current receiving connection terminals, and a load connected to the storage battery, the power supply apparatus for charging-type device comprising relay contacts of a relay connected to a primary side of a primary winding of the transformer, short-circuit contacts for the relay contacts, a relay coil for opering and closing the relay contacts, a first connection control terminal connected to the relay coil, and a second connection control terminal capable of being coupled and detached from the first connection control terminal, the relay coil being connected to a secondary side of secondary winding of the transformer via the first and second control terminals to interrupt a current flowing through the transformer upon completion of battery charging and upon detachment of the charging-type device from the main body of the power supply apparatus.