A bearing apparatus of a crankshaft for an internal combustion engine, the bearing apparatus comprising: a crankshaft including a plurality of journal portions (61, 62) and a plurality of crank pin portions; main bearings (41, 42) supporting the crankshaft; and a bearing housing holding the main bearings (41, 42), wherein the plurality of journal portions includes a first journal portion having a lubricating oil passage for supplying oil to the crank pin portions of the crankshaft and a second journal portion not having the lubricating oil passage, the first journal portion is supported by a first main bearing; and the first main bearing includes a pair of semi-cylindrical shaped upper half bearing and lower half bearing, the second journal portion is supported by a second main bearing; and the second main bearing includes a pair of semi-cylindrical shaped upper half bearing and lower half bearing, the bearing housing includes an Al alloy upper housing and an Fe alloy lower housing; the upper housing has a semi-cylindrical surface aligned with an outer peripheral surface of the upper half bearing; the lower housing has a semi-cylindrical surface aligned with an outer peripheral surface of the lower half bearing; the upper half bearings (41U, 42U) are held by the semi-cylindrical surface of the upper housing; and the lower half bearings (41L, 42L) are held by the semi-cylindrical surface of the lower housing, an internal oil passage for supplying oil to the first and second main bearings is formed inside the upper housing; and an opening (G2c) of the internal oil passage is formed in the semi-cylindrical surface of the upper housing, only the upper half bearings (41U, 42U) of the pairs of half bearings have oil grooves (41G, 42G) formed in the inner peripheral surface and at least one oil hole, the oil hole penetrates the bearing wall thickness of the upper half bearings (41U, 42U) and opens in the outer peripheral surface, the opening (G2c) of the internal oil passage of the upper housing communicates with the oil grooves (41G, 42G) through the oil hole, the upper and lower half bearings (41U, 41L, 42U, 42L) include crash reliefs at circumferential end portions of inner peripheral surfaces thereof, a range where the oil groove of the upper half bearing of the first main bearing is formed in the circumferential direction is a range where each of the circumferential end portions of the oil groove communicates with the crash relief at a minimum distance and opens in a circumferential end face of the upper half bearing of the first main bearing at a maximum distance, the oil groove of the upper half bearing of the second main bearing being formed in the circumferential direction in a range of a circumferential angle of ±45° with respect to a circumferential center portion of the upper half bearing of the second main bearing at a maximum distance, and in a range of a circumferential angle of at least 10° in a region of a circumferential angle of ±45° with respect to the circumferential center portion of the upper half bearing of the second main bearing, and a groove depth of the oil groove of the upper half bearing of the second main bearing is one half or less than a groove depth of the oil groove of the upper half bearing of the first main bearing.