Apparatus for and method of mass analysis

An apparatus for mass analysis, the apparatus analyzing a sample containing a target substance, which is an organic compound, and one or more interfering substances, which are organic compounds and have a peak of a mass spectrum overlapping that of the target substance, the apparatus comprising:

• among peaks of a mass spectrum of a reference material of each of the interfering substances, based on a nonlinear relation F of intensities between peak A that does not overlap a peak of a mass spectrum of the target substance and peak B that overlaps the peak of the target substance,
• a peak correction unit calculating an intensity of net peak D of the mass spectrum of the target substance by subtracting a total sum of estimated intensities of the peak B, which are calculated at every predetermined time interval based on the intensities of the peak A and the relation F, from an intensity of peak C of a mass spectrum of the target substance of the sample.