The present invention relates to a method for preparing an protein monolayer using a peptide hybrid for protein immobilization, more precisely a peptide hybrid for protein immobilization which has improved solubility by introducing a PEG linker and a proper reaction group to the oligopeptide having specific affinity to selected types of proteins and is designed to provide enough space between solid substrates and proteins immobilized, whereby various solid substrates treated by the hybrid catch specific proteins effectively on. The peptide hybrid for protein immobilization of the present invention facilitates the control of orientation of an antibody on various solid surfaces and immobilization of various antibodies of different origins or having different isotypes with different affinity. Therefore, the surface treatment technique using the peptide hybrid of the invention can be effectively used for the production of various immunosensors and immune chips.