A direct search for new particles in the H1 experiment at HERA is pres
ented for masses ranging from 35 GeV up to approximately 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, leptoglu
ons, excited electrons and excited neutrinos with flavours of the firs
t generation. No evidence for the production of such particles was fou
nd in various possible decay channels. Rejection limits are derived.