A magnetic lock which may serve, itself, as a locking device, or may form part of an otherwise conventional locking device, is provided with a body member, detent balls, and a detent locking plunger that is disposed in an axially extending interior space of the body member in a manner enabling the locking plunger to be displaced within the body member between a first location, at which the locking plunger causes the detent balls to be locked in a position protruding from the body member, and a second location at which the locking plunger enables the detent balls to retract into the body member. The body member is provided with a sealed end having a key seat upon which a key may be seated for shifting the locking plunger between its first and second locations. The key is provided with at least one magnet that emanates a magnetic flux, and at least one second magnet is disposed in the interior space so as to emanate a magnetic flux which will interact with the flux of the magnet of the key when the key is seated on the key seat. Additional security is provided for preventing the unlocking of the magnetic lock by the mere positioning of the key on the key seat. Unlocking may occur only after a predetermined manipulation of the key means has been carried out on the key seat.