Interface apparatus and method of element that can change length

PURPOSE: An interface device and a method of an element having the change available length considering elasticity are provided to arrange elements, thereby conveniently performing change an proceed of the element. CONSTITUTION: An interface device includes a display unit(120), an interface unit(110) and a control unit(130). The display unit displays a reference axis for elements and arrangement of the elements. According to the elasticity, the length of element can be transformed. The interface unit sense manipulation about the element. According to the sensed manipulation, the control unit changes the display state of the element.