PURPOSE: To make efficient the take-out of a sorted sheet block by applying the constitution wherein the partial length of the sheet block is taken out for half taking when sheet blocks are taken out in turn from a sheet block formation part.

CONSTITUTION: A sheet (a) is continuously supplied on a conveyor 1 and stacked on the tray 2 of a sheet block formation part B until the number of sheets reaches the predetermined level, thereby forming a preceding sorted sheet block A1. Consequently, a sorting claw 3 works upon the front end part (temporary receipt position) of the block A1 and receives temporarily a succeeding sheet (a). Then, during the aforesaid temporary receiving process, grippers 4 and 5 clamp the front end of the block A1 and takes out a half of the block A1 forward (for example, half W2 of block A1). Thereafter, the claw 3 is kept at a standby position. According to the aforesaid construction, the sheet (a) is stacked on the top of the rear side of the preceding sorted sheet block A1 and a succeeding sorted sheet block A2 is formed. In this state, the overlapped part of the blocks A1 and A2 is gripped with the grippers 4 and 5 for taking out a half as W2.