As a new method for measuring the R-CID spectra of solid samples, we attempted to obtain the spectra by melting samples into liquid state. That is, the special R-CID cell for high temperature use was made and the R-CID spectra ofl-menthol andl-pantoyl lactone in the molten state were measured. The signal to noise ratios of their spectra were improved when compared with those in the solution state. It can be expected that the number of measurable solid samples in the R-CID spectroscopy should increase by use of the technique developed here.