An all-purpose engine, comprising: an intake member which accommodates a filter part and has an opening, leading to a carburetor, in an end wall opposing the filter part; an opening/closing member which is disposed between the filter part and the end wall, and opens/closes the opening; and a working member which is disposed on an opposite side to the opening/closing member so as to interpose the end wall, and allows the opening/closing member to be operated, wherein the intake member has a cylindrical boss part which projects to an opposite side than the filter part to interpose the end wall, and constitutes a passage that returns a gas returned from a side of the carburetor to the carburetor via the opening, wherein the boss part is provided above the opening in the gravity direction of the intake member, wherein the working member includes: an arm part which extends along the end wall and is linked with the opening/closing member to interpose the end wall at one end part, and a holding part provided to another end part of the arm part, wherein the arm part has a bend section which is bent in a substantially semicircular arc shape and accommodates the boss part at an inner side, wherein the intake member, at a rear side, has a guide hole into which the arm part is inserted and guides movement of the arm part, and wherein the holding part is disposed to project from the guide hole to a side of a rear side wall arranged at the rear side of the intake member, among side walls surrounding a periphery of the end wall, is provided to be wider than the arm part, extends towards the opposite side to the carburetor along the rear side wall from the arm part and has a notch part at a surface opposing the rear side wall of the intake member, wherein the notch part is obliquely notched out so as to gradually become a narrow shape toward a linking part with the arm part. an intake member which accommodates a filter part and has an opening, leading to a carburetor, in an end wall opposing the filter part; an opening/closing member which is disposed between the filter part and the end wall, and opens/closes the opening; and a working member which is disposed on an opposite side to the opening/closing member so as to interpose the end wall, and allows the opening/closing member to be operated, wherein the intake member has a cylindrical boss part which projects to an opposite side than the filter part to interpose the end wall, and constitutes a passage that returns a gas returned from a side of the carburetor to the carburetor via the opening, wherein the boss part is provided above the opening in the gravity direction of the intake member, wherein the working member includes: an arm part which extends along the end wall and is linked with the opening/closing member to interpose the end wall at one end part, and a holding part provided to another end part of the arm part, wherein the arm part has a bend section which is bent in a substantially semicircular arc shape and accommodates the boss part at an inner side, wherein the intake member, at a rear side, has a guide hole into which the arm part is inserted and guides movement of the arm part, and wherein the holding part is disposed to project from the guide hole to a side of a rear side wall arranged at the rear side of the intake member, among side walls surrounding a periphery of the end wall, is provided to be wider than the arm part, extends towards the opposite side to the carburetor along the rear side wall from the arm part and has a notch part at a surface opposing the rear side wall of the intake member, wherein the notch part is obliquely notched out so as to gradually become a narrow shape toward a linking part with the arm part.