A method of manufacturing packages includes forming grooves with a depth that reaches a finished thickness of a device chip along planned dividing lines from a front surface of a device wafer, sealing the front surface of the device wafer by a sealant and filling the grooves with the sealant, and grinding a back surface of the device wafer corresponding to a device region to form a recessed part with a depth that reaches the grooves and forms an annular projection part that surrounds the recessed part and corresponds to a peripheral surplus region. The recessed part is filled with the sealant to execute sealing and dividing grooves are formed with a smaller width than the grooves along the grooves from the front surface of the device wafer. The device wafer is divided to form plural packages in each of which the device chip is sealed by the sealant.