Tank having integrated insulation structure

A water purifier comprising:

• a filter unit filtering introduced raw water to generate purified water;
• a tank having an integrated insulation structure storing water filtered by the filter unit;
• and
• an extraction unit supplying purified water accommodated in the tank having an integrated insulation structure to a user,
• wherein the tank comprising:
• a tank body having an accommodating space formed therein;
• a foamed case surrounding an outer circumferential surface of the tank body;
• and
• a foamed insulation material formed as a foaming agent introduced to a foaming space between the outer circumferential surface of the tank body and the foamed case is foamed,
• wherein the foamed insulation material is integrated with the tank body and the foamed case through foaming,
• the foamed case includes a plurality of portions surrounding the tank body, and
• at least some of the plurality of portions has a structure manufactured in an unfolded view shape to be folded thereafter to correspond to the outer circumferential surface of the tank body.