PURPOSE: To solve such problem that erroneous detection occurs by making a coin coming off a rail by increasing the inclination of the rail to accelerate selection speed since the coin rolling on and dropping from the rail of a coin passage is detected by a conventional coin selector using a coil sensor.

CONSTITUTION: Two pairs of coil sensors 2-1, 2-2 are placed at positions symmetric in a width direction against a center line bisecting the passage width of the coin passage, and prescribed correction (a) (A-B)2 in proportion to the square of the difference (A-B) of the outputs of both sensors is applied to the sum (A+B) of the output of both sensors, thereby, detection quantity (A+ B+a(A-B)2) not relating to a coin passing position can be obtained.