PURPOSE: To compact the whole apparatus and improve the operating efficiency in a machine for preparing a bulb capable of cutting the root part and stem part of the bulb such as an onion and removing the epidermis.

CONSTITUTION: The objective machine for preparing a bulb is constructed by installing a transverse conveying trough 15 for guiding an onion subjected to the cutting treatment in the transverse direction in the conveying terminal end of an onion conveying passage 2 provided with a root part cutting means 6 and a stem part cutting means 7 and further arranging a rough skin (epidermis) removing means 3 for removing the rough skin while conveying the onion so as to provide the side of the transverse conveying trough 15 as the starting end and the side of the conveying starting end of the onion conveying passage 2 as the terminal end so as to locate a carrying in position and a discharging position of the onion on the same side.