Sheet manufacturing apparatus and control method for sheet manufacturing apparatus

A sheet manufacturing apparatus comprising:

• an accumulating unit that includes a drum in which a plurality of openings are formed, and discharges fibers by causing the fibers to pass through the openings by rotating the drum;
• a web forming unit that includes a belt on which the fibers passing through the openings are accumulated, and forms a web by operating the belt;
• a sheet forming unit that forms a sheet from the web formed by the web forming unit;
• and
• a control unit that performs a start control for operating the accumulating unit and the web forming unit from a stop state,
• in performing the start control from a state where the fibers are present in the drum, the control unit controlling a timing at which rotation of the drum is initiated and a timing at which movement of the belt is initiated, thereby adjusting a thickness of the web formed by the web forming unit.