Gusset windows according to the present invention is a Gusset fittings to be attached to an existing windows and doors including a sealant which is installed at the changjjak and said glass to secure the glass and the glass on which the glass and the changjjak close contact so as to be fixed to the changjjak , one side is inserted into the sealant is fixed on the other side of the bracket and the bracket is secured between the glass and the changjjak includes a deotchang are installed to be spaced apart the glass and the predetermined distance.