A sealing film with a hidden tab includes a bottom layer and a top layer. The bottom layer includes a heat sealing layer, an aluminum foil layer, and a polypropylene layer. The top layer includes a nylon layer and a polyethylene terephthalate layer, and is defined with a connection portion and a tab portion. The nylon layer in the connection portion is adhered to the polypropylene layer by an adhesive. At least a contact is disposed between the nylon layer in the tab portion and the polypropylene layer. Due to physical properties of the material of which the nylon layer in the tab portion is made, the sealing film is likely to sever but easy to peel off. The contact not only prevents the tab portion of the top layer from warping but also enables a user to determine whether the sealing film has ever been used before.