A direct search for new particles in the H1 experiment at HERA is presented for masses ranging from 35 GeV up to ∼ 250 GeV. The data sample of 24 nb-1 accumulated during the first year of operation was analysed for signatures of scalar and vector leptoquarks, leptogluons, excited electrons and excited neutrinos with flavours of the first generation. No evidence for the production of such particles was found in various possible decay channels. Rejection limits are derived. © 1993.