A bearing structure comprising: a crankshaft rotatably supported by a crankshaft bearing part formed of a cylinder block of an internal combustion engine and a first bearing cap through a bearing metal; and a second shaft rotatably supported by a second shaft bearing part formed of the first bearing cap and a second bearing cap; characterized in that the bearing metal has: a bearing metal oil groove portion formed with an oil groove formed to extend circumferentially in an inner peripheral surface of the bearing metal, the inner peripheral surface at which the bearing metal oil groove portion is formed; a bearing metal planar portion for rotatably supporting the crankshaft with an entire inner peripheral surface of the bearing metal in which the oil grove is not formed, the inner peripheral surface at which the bearing metal planar portion is formed; a first oil hole opening at the oil groove; and a second oil hole opening at the oil groove, wherein the bearing metal planar portion is set at a position in a load direction where a load is applied to the crankshaft when combustion pressure is maximal, wherein the cylinder block is formed with an in-block oil passage communicating with the first oil hole and supplying oil from an oil gallery of the cylinder block to the crankshaft bearing part, and wherein the first bearing cap is formed with an in-cap oil passage communicating with the second oil hole and supplying the oil from the crankshaft bearing part to the second shaft bearing part. a crankshaft rotatably supported by a crankshaft bearing part formed of a cylinder block of an internal combustion engine and a first bearing cap through a bearing metal; and a second shaft rotatably supported by a second shaft bearing part formed of the first bearing cap and a second bearing cap; characterized in that the bearing metal has: a bearing metal oil groove portion formed with an oil groove formed to extend circumferentially in an inner peripheral surface of the bearing metal, the inner peripheral surface at which the bearing metal oil groove portion is formed; a bearing metal planar portion for rotatably supporting the crankshaft with an entire inner peripheral surface of the bearing metal in which the oil grove is not formed, the inner peripheral surface at which the bearing metal planar portion is formed; a first oil hole opening at the oil groove; and a second oil hole opening at the oil groove, a bearing metal oil groove portion formed with an oil groove formed to extend circumferentially in an inner peripheral surface of the bearing metal, the inner peripheral surface at which the bearing metal oil groove portion is formed; a bearing metal planar portion for rotatably supporting the crankshaft with an entire inner peripheral surface of the bearing metal in which the oil grove is not formed, the inner peripheral surface at which the bearing metal planar portion is formed; a first oil hole opening at the oil groove; and a second oil hole opening at the oil groove, wherein the bearing metal planar portion is set at a position in a load direction where a load is applied to the crankshaft when combustion pressure is maximal, wherein the cylinder block is formed with an in-block oil passage communicating with the first oil hole and supplying oil from an oil gallery of the cylinder block to the crankshaft bearing part, and wherein the first bearing cap is formed with an in-cap oil passage communicating with the second oil hole and supplying the oil from the crankshaft bearing part to the second shaft bearing part.