To provide an apparatus for detecting the number of blanks, in which resetting and readjustment are not required and the number of blank materials (metal sheets) is stably detected even if the size and the shape of a blank material are greatly varied.

This apparatus is provided with a plurality of support members 12 the upper ends of which are situated dispersedly in the horizontal direction and which are extended downward through the clearances of conveying equipment, an elevating and lowering device 14 which is elevated and lowered between the "retracting position" L where the upper ends of the support member are situated below the blank material supporting face of the conveying equipment and the "supporting position" H where the upper end is situated above the blank material supporting face and with which the blank material is supported, a weight measuring device 16 for measuring the total weight which acts on the lower end of the support member and an arithmetic unit 18 for calculating the number of the blank materials from the measured value of the total weight in the supporting position H.