A sheet manufacturing apparatus having: a defibrating unit configured to defibrate, in air, feedstock containing fiber; a mixing unit configured to mix, in air, resin with the fiber defibrated from the feedstock by the defibrating unit; an air-laying unit configured to lay a web from the mixture output from the mixing unit; a liquid application unit configured to add water to part of the web laid by the air-laying unit; and a sheet forming unit configured to form a sheet with parts having different light transmittance by heating and compressing the web to which water was added by the liquid application unit.