PURPOSE: A filter is provided to effectively filter an impurity from a fluid. A filter section is effectively inserted into a case in an original state or disassembled without an additional work. CONSTITUTION: A filter comprises a case(101); and a filter section(110). The case comprises an inlet and an exit of a fluid. The filter section is inserted into the case and filters an impurity from a fluid. The filter section is a form in which multiple filters are interconnected. A connection type is varied when a power is applied in a connection part between filters. Filters are interconnected and a closed loop is formed. Filters are interconnected by a hinge-joint.
