The developer for electrostatic photography according to the present invention comprises toner particles containing a thermoplastic resin and a colorant dispersed in an electrically insulating carrier having a melting point above room temperature wherein the thermoplastic resin is insoluble in the electrically insulating carrier at a temperature below the melting point of the electrically insulating carrier but becomes solvated with the electrically insulating carrier at a temperature above the melting point of the electrically insulating carrier. The present invention provides a developer for electrostatic photography, which enables to reduce the emission of vapor, to carry out a fixing treatment at a higher rate, to reduce the amount of energy required for fixing treatment and to create a high-quality image even after repeated use of the developer.