PURPOSE: To make the titled machine movable with low cost and less space, by providing a number setting section selecting and setting a code number specific to a buyer registered in advance by the operation of the buyer and a response button depressed at offer.

CONSTITUTION: Number setting sections 31W33 comprise respectively digital switches, the number of 0W9 is displayed respectively on the switches 31W33, which are possible for turning. A buyer using this input device sets selectively the code number specific to the buyer registered in advance with the switches 31W33 and moves a lever to the LOCK position. The buyer taking part in an auction inserts a connector 8 into a receptacle of a seat selected by the buyer and operates the response button 2 depending whether the buyer applies the offer or not.