An evaporator comprising: a case formed in an empty box type and having a storage chamber therein; a cooling tube formed on the case in a preset pattern and filled with refrigerant for cooling therein; a heating tube formed on the case in a preset pattern so as not to be overlapped with the cooling tube and filled with working fluid for defrosting therein; and a heating unit fixed to an external surface of the case corresponding to the heating tube and configured to heat the working fluid within the heating tube, the heating tube includes: a chamber to which the heating unit is fixed to heat the working fluid contained therein and including an outlet through which the working fluid which has been heated by the heating unit is discharged and an inlet through which the working fluid which has been cooled is collected; and a flow tube coupled to the outlet and the inlet, respectively to form a flow path through which the working fluid flows, characterized in that the heating unit includes: a mounting frame disposed so as to cover the chamber; a heater fixed to the mounting frame; a lead wire configured to electrically connect the heater to a controller; and a sealing member disposed so as to cover the heater. a case formed in an empty box type and having a storage chamber therein; a cooling tube formed on the case in a preset pattern and filled with refrigerant for cooling therein; a heating tube formed on the case in a preset pattern so as not to be overlapped with the cooling tube and filled with working fluid for defrosting therein; and a heating unit fixed to an external surface of the case corresponding to the heating tube and configured to heat the working fluid within the heating tube, the heating tube includes: a chamber to which the heating unit is fixed to heat the working fluid contained therein and including an outlet through which the working fluid which has been heated by the heating unit is discharged and an inlet through which the working fluid which has been cooled is collected; and a flow tube coupled to the outlet and the inlet, respectively to form a flow path through which the working fluid flows, characterized in that the heating unit includes: a mounting frame disposed so as to cover the chamber; a heater fixed to the mounting frame; a lead wire configured to electrically connect the heater to a controller; and a sealing member disposed so as to cover the heater. a chamber to which the heating unit is fixed to heat the working fluid contained therein and including an outlet through which the working fluid which has been heated by the heating unit is discharged and an inlet through which the working fluid which has been cooled is collected; and a flow tube coupled to the outlet and the inlet, respectively to form a flow path through which the working fluid flows, characterized in that the heating unit includes: a mounting frame disposed so as to cover the chamber; a heater fixed to the mounting frame; a lead wire configured to electrically connect the heater to a controller; and a sealing member disposed so as to cover the heater. a mounting frame disposed so as to cover the chamber; a heater fixed to the mounting frame; a lead wire configured to electrically connect the heater to a controller; and a sealing member disposed so as to cover the heater.