A method of manufacturing an image forming apparatus having an envelope made of members inclusive of a first substrate and a second substrate disposed at a space being set therebetween, image forming means and spacers disposed in the envelope, the spacers maintaining the space, the method including the steps of forming a spacer having a desired shape by cutting a spacer base member, and abutting the spacer upon the first and second substrates at a non-cut surfaces of the spacer.