To provide an inlet plural-row stacker capable of facilitating adjustment of intervals between a plurality of rows of stackers and adjustment of inlet flat stack height sensing by a sensor in accordance with the sizes of and intervals between stored inlets, etc.

The stacker includes on a bottom plate 51: a predetermined number of storage part engagement members 54 axially movable corresponding to a predetermined number of guide shafts 46-48 extending in the row direction; an inlet storage part 52 in which the inlets as individual pieces are stacked flatly; and a sensor S sensing the flat stack height of the inlets stored in the inlet storage part 52. The stacker further includes: a sensor block 56 to which a sensor turning adjustment shaft 44 extending in the row direction and having a non-circular cross section is penetrated and which is rotated together with turning of the sensor turning adjustment shaft 44; and a sensor support member 53 movable with respect to the axial direction of the sensor turning adjustment shaft 44 and supporting the sensor block 56.