Fuel supply device (10) may comprise fuel pump (20) and suction filter (40) attached to a fuel intake port (36) of fuel pump (20). Suction filter (40) may have a sheet-shaped filter body (38) and an attaching member (29). Filter body (38) has an internal filter structure (40a, 40b), and attaching member (29) attaches filter body (38) to fuel intake port (36) such that internal filter structure (40a, 40b) communicates with fuel intake port (36). Filter body (38) may be folded over to form a multi-layered structure comprising an upper filter layer (38a) and a lower filter layer (38b). Folding over the sheet-shaped filter body (38) allows a filtration area of fuel supply device (10) to be increased while preventing an increase in the size of fuel supply device (10).