Bench-top time of flight mass spectrometer

An assembly for a mass spectrometer comprising: a housing; and, a time of flight (ToF) analyser 110 enclosed within and cantilevered from the housing. The ToF analyser comprises a pusher assembly 120 and a flight tube 160, which are preferably mounted to a support assembly 130 of the ToF analyser, the support being cantilevered from the housing. The support may have a main body 142, to which the flight tube and pusher are attached, and a connecting member 132, for fastening to the housing. The connecting member may be a horseshoe or U-shaped bracket connected to the housing by thermally and/or electrically insulating fasteners, preferably extending through apertures 138. A reflectron 170 may be mounted to the flight tube with insulating fasteners. The insulating fasteners may be formed of ceramic or plastic, such as polyether ether ketone (PEEK).