A tape dispenser that includes a seat and a cover. The seat includes a acting portion for installing and cutting a tape, and a support portion connecting to the acting portion and supporting the acting portion to be placed on a surface. The support portion includes a first pivotal portion and a first adhesion portion for adhering to the surface. The cover is pivotally connected to the support portion, and includes a second pivotal portion pivotally engaged with the first pivotal portion, and a covering portion connected to the second pivotal portion and formed at an area larger than that of the first adhesion portion. The covering portion comprises a first position at which the covering portion covers the first adhesion portion, and a second position at which the covering portion is disengaged from the first adhesion portion to make the first adhesion portion adhere to the surface.