A tweezer-type hand-held device for installing and removing an electric part on and from a substrate. The device is provided with a pair of legs biased to close such that the part is held between the legs by the biasing force when the part is installed on the substrate. In an embodiment, one of the legs may be biased in two directions, i.e. in a direction to open and in another direction to close, and a switching member is disclosed to switch the biasing direction. The biasing member may include a spring commonly used for the biasing in the two directions. Manipulation portions are provided for open or close the legs against the force of the biasing member.