The ceiling concealed air-conditioning apparatus includes: a body containing a heat exchanger, a fan and an opening port; a decorative panel disposed below the body and configured to cover a periphery of the opening port; and a suction grille including, a rotary shaft attachable to the decorative panel and being configured to cover the opening port, wherein the suction grille includes: a locking element mounted on the suction grille so that it can slide and configured to be locked with the decorative panel; plate springs on respective sides of the locking element perpendicular to a sliding direction of the locking element and extending vertically in opposite directions; and spring supports configured to support both end faces of the respective plate springs at different positions, the plate springs include a long plate spring and a short plate spring placed such that the long plate spring engages the decorative panel first.