An air conditioner that is a wall-hung type air conditioner comprising: a heat exchanger; a fan; and an electric equipment box in a main body of an indoor unit, wherein said electric equipment box includes a container portion made of resin containing a control board, a terminal block and said electric equipment box is characterised in that the container portion having an opening portion with a locking claw on an outer peripheral face; a case made of sheet metal having an opening portion with a locking hole engaged with the locking claw of said container portion on an outer periphery thereof; a cover made of resin having an opening portion with a locking claw on an outer peripheral face thereof; and a lid body made of sheet metal having an opening portion with a locking hole engaged with the locking claw of said cover on an outer periphery thereof, wherein the locking claw of said container portion is engaged with the locking hole of said case so that said case covers the outer peripheral face of the container portion, the locking claw of said cover is engaged with the locking hole of said lid body so that said lid body covers the outer peripheral face of said cover, by assembling an opening edge of the opening portion of said case covering said container portion to be covered by an opening edge of the opening portion of said cover covered by said lid body, a locking part of the locking claw of said container portion with the locking hole of said case is configured to be covered by said lid body and said cover and said lid body are fixed to said container portion and said case; and between an opening end of said lid body and an opening end of said case, a flame spread inhibiting path of a predetermined length is formed in which the opening edge of said lid body and the opening edge of said case overlap. a heat exchanger; a fan; and an electric equipment box in a main body of an indoor unit, wherein said electric equipment box includes a container portion made of resin containing a control board, a terminal block and said electric equipment box is characterised in that the container portion having an opening portion with a locking claw on an outer peripheral face; a case made of sheet metal having an opening portion with a locking hole engaged with the locking claw of said container portion on an outer periphery thereof; a cover made of resin having an opening portion with a locking claw on an outer peripheral face thereof; and a lid body made of sheet metal having an opening portion with a locking hole engaged with the locking claw of said cover on an outer periphery thereof, wherein the locking claw of said container portion is engaged with the locking hole of said case so that said case covers the outer peripheral face of the container portion, the locking claw of said cover is engaged with the locking hole of said lid body so that said lid body covers the outer peripheral face of said cover, by assembling an opening edge of the opening portion of said case covering said container portion to be covered by an opening edge of the opening portion of said cover covered by said lid body, a locking part of the locking claw of said container portion with the locking hole of said case is configured to be covered by said lid body and said cover and said lid body are fixed to said container portion and said case; and between an opening end of said lid body and an opening end of said case, a flame spread inhibiting path of a predetermined length is formed in which the opening edge of said lid body and the opening edge of said case overlap.