A meter is mounted to an instrument panel. The meter has an engaging portion in the form of a projection-like rotation shaft and projections located on the side walls of the meter. The instrument panel has a support groove and guide grooves. The meter is inserted into the instrument panel so that the projection-like rotation portion engages with the support groove of the panel. The meter is rotated about the projection-like rotation portion while the projections on the side wall of the meter engage with the guide grooves of the instrument panel.