To provide an automatic envelope set replacing and collating band applying machine capable of collating a predetermined number of bags of sealed envelopes having a predetermined number of lottery tickets sealed therein as one set in a continuous manner and collecting them as the predetermined number of sets to perform a band applying operation.

There are provided ten units of envelope feeders (1) for intermittently feeding out one by one the envelopes having ten lottery tickets sealed therein; a collating and transferring conveyor device (2) for stacking up in sequence each of the fed-out envelopes; a window inspecting device (3) for reading out and inspecting the number indicated in a lottery ticket through the window part of the upper-most envelope in ten envelopes stacked up and collated on the collating and transferring conveyor device (2); a base sheet discharging unit (4) for collecting ten base sheets and discharging them together; a thickness inspecting unit (5) for inspecting a thickness of envelopes in ten bags; a stacking-up unit (6) for stacking-up ten units of envelopes with envelopes of ten bags being applied as one set; and band applying units (8, 9) for applying a band to envelopes of ten sets transferred from the stacking-up unit (6) through the stacking-up and transferring conveyor device (7).