A method and an installation (10) for removing slag allows both slag removal and metal recovery from slag (60) to be performed quickly and easily. The risk of slag fires is reduced.

When molding surfaces (50A) of a pair of dies (50) are to be cleaned by air-blowing, air is blown towards the molding surfaces (50A) from blowing nozzles (22A) of a cleaning blowing function portion (22) while a moving body (16) is reciprocatingly moved by driving force of a driving mechanism (18). When a parting agent is to be applied to the molding surfaces (50A) of the pair of dies (50), the mold release agent is jetted out towards the molding surfaces (50A) from spraying nozzles (24A) of a parting agent application function portion (24) while the moving body (16) is reciprocatingly moved by the driving force of the driving mechanism (18). In both of these situations, at the same time as the treatment of the molding surfaces (50A), a cleaning brush (32) reciprocatingly moves together with the moving body (16) and sweeps a device floor surface (12).