A vibratory sieving machine comprising a sieving net and means for vibrating the sieving net which means comprise a vibration generating machine comprising two rotary shafts (31a, 31b) provided with eccentric spindles (32a, 32b) disposed parallel to each other, motors (Ma, Mb) configured such that the two rotary shafts (31a, 31b) can be driven independently, bearings (33a, 33b) of the rotary shafts (31a, 31b), and a rotary drive control mechanism configured so that transmission of rotary drive force to either one of the two rotary shafts (31a, 31b) is suspended after the rotary drive state of the two rotary shafts (31a, 31b) is transferred to a stationary state, and further configured so that the rotary shaft having suspended the transmission of the rotary drive force is rotated along with cooperation of the other rotary shaft vibrated by the generation of the rotary drive of the other rotary shaft, and wherein selection of the rotary shaft for stopping transmission of rotary drive force causes a difference in the angle of vibrating direction wherein the angle of the vibrating direction is set by adjusting the angle formed by the plane including the central axis of the two rotary shafts (31a, 31b) with the horizontal plane, characterized in that the vibration generating machine further comprises a casing and in that the vibratory sieving machine further comprises a vibratory pump, a reservoir unit of lubricating oil (Oi) and a strainer, wherein the vibratory pump is configured to supply lubricating oil from the reservoir unit into the bearings of the rotary shafts such that lubricating oil supplied into the bearings is sent back to the reservoir unit through the strainer for removing foreign matter in the casing and in the lubricating oil. comprising a sieving net and means for vibrating the sieving net which means comprise a vibration generating machine comprising two rotary shafts (31a, 31b) provided with eccentric spindles (32a, 32b) disposed parallel to each other, motors (Ma, Mb) configured such that the two rotary shafts (31a, 31b) can be driven independently, bearings (33a, 33b) of the rotary shafts (31a, 31b), and a rotary drive control mechanism configured so that transmission of rotary drive force to either one of the two rotary shafts (31a, 31b) is suspended after the rotary drive state of the two rotary shafts (31a, 31b) is transferred to a stationary state, and further configured so that the rotary shaft having suspended the transmission of the rotary drive force is rotated along with cooperation of the other rotary shaft vibrated by the generation of the rotary drive of the other rotary shaft, and wherein selection of the rotary shaft for stopping transmission of rotary drive force causes a difference in the angle of vibrating direction wherein the angle of the vibrating direction is set by adjusting the angle formed by the plane including the central axis of the two rotary shafts (31a, 31b) with the horizontal plane, characterized in that the vibration generating machine further comprises a casing and in that the vibratory sieving machine further comprises a vibratory pump, a reservoir unit of lubricating oil (Oi) and a strainer, wherein the vibratory pump is configured to supply lubricating oil from the reservoir unit into the bearings of the rotary shafts such that lubricating oil supplied into the bearings is sent back to the reservoir unit through the strainer for removing foreign matter in the casing and in the lubricating oil.