A filter comprising: an inlet (110, 210, 310) through which a fluid is introduced; a channel portion (130, 230, 330) connected to the inlet, wherein a ratio of width to length of the channel portion ranges from 3:1 to 100:1; a first connecting portion (120, 220) that connects the inlet (110, 210, 310) and the channel portion (130, 230, 330) and having a tapered structure that widens in a direction from the inlet (110, 210, 310) to the channel portion (130, 230, 330); an outlet (150, 250, 350) connected to the channel portion and through which the fluid is discharged; a second connecting portion (140, 240) that connects the channel portion (130, 230, 330) and the outlet (150, 250, 350) and having a tapered structure that narrows in a direction from the channel portion (130, 230, 330) to the outlet (150, 250, 350); at least one fluid resisting portion (160, 260, 360) disposed between the inlet and the outlet, wherein the at least one fluid resisting portion has a shape of a diamond, a triangle, a quadrangle, a circle, an oval, a fan shape, or a streamlined shape, wherein a first fluid resisting portion (160, 260, 360) extends substantially across a width of the first connecting portion (120, 220) and substantially along a length from the first connecting portion (120, 220) to the channel portion (130, 230, 330), wherein the first fluid resisting portion (160, 260, 360) is appropriately sized so as to allow fluid including target materials to flow from the inlet around the first fluid resisting portion (160, 260, 360) and to the outlet; and a filter portion disposed within the channel portion (130, 230, 330) and between the first fluid resisting portion (160, 260, 360) and the outlet (150, 250, 350) to capture the target materials included in the fluid. an inlet (110, 210, 310) through which a fluid is introduced; a channel portion (130, 230, 330) connected to the inlet, wherein a ratio of width to length of the channel portion ranges from 3:1 to 100:1; a first connecting portion (120, 220) that connects the inlet (110, 210, 310) and the channel portion (130, 230, 330) and having a tapered structure that widens in a direction from the inlet (110, 210, 310) to the channel portion (130, 230, 330); an outlet (150, 250, 350) connected to the channel portion and through which the fluid is discharged; a second connecting portion (140, 240) that connects the channel portion (130, 230, 330) and the outlet (150, 250, 350) and having a tapered structure that narrows in a direction from the channel portion (130, 230, 330) to the outlet (150, 250, 350); at least one fluid resisting portion (160, 260, 360) disposed between the inlet and the outlet, wherein the at least one fluid resisting portion has a shape of a diamond, a triangle, a quadrangle, a circle, an oval, a fan shape, or a streamlined shape, wherein a first fluid resisting portion (160, 260, 360) extends substantially across a width of the first connecting portion (120, 220) and substantially along a length from the first connecting portion (120, 220) to the channel portion (130, 230, 330), wherein the first fluid resisting portion (160, 260, 360) is appropriately sized so as to allow fluid including target materials to flow from the inlet around the first fluid resisting portion (160, 260, 360) and to the outlet; and a filter portion disposed within the channel portion (130, 230, 330) and between the first fluid resisting portion (160, 260, 360) and the outlet (150, 250, 350) to capture the target materials included in the fluid.