An image reading apparatus configured to read an image of a manuscript, the apparatus comprising: a main body; a contact glass provided at an upper surface of the main body to set the manuscript thereon; an image sensor provided on a side opposite to a surface of the contact glass on which the manuscript is set, the image sensor extending in a first direction and having a reading surface which faces the contact glass to read the image from the manuscript on the contact glass; a rail member extending inside the main body in a second direction perpendicular to the first direction and parallel to the surface of the contact glass on which the manuscript is set; a carriage which is supported by the rail member to be slidable along the second direction and contains the image sensor in a sensor container having a recess open to a contact glass side, the carriage being supported to be swingable about the rail member at a central portion thereof in the first direction, and having a taper end portion (32, 33) which is formed in an end portion thereof in the first direction to be smaller in height toward an end side and an opening (34, 35) penetrating a bottom surface of the sensor container such that an end portion of the image sensor may project downward below the bottom surface of the carriage on a side of the taper end portion (32, 33); a biased portion which is provided adjacent to the reading surface of the image sensor in the second direction on the side of the taper end portion (32, 33); and a biasing member provided between the biased portion and the carriage to bias the image sensor toward the contact glass via the biased portion. a main body; a contact glass provided at an upper surface of the main body to set the manuscript thereon; an image sensor provided on a side opposite to a surface of the contact glass on which the manuscript is set, the image sensor extending in a first direction and having a reading surface which faces the contact glass to read the image from the manuscript on the contact glass; a rail member extending inside the main body in a second direction perpendicular to the first direction and parallel to the surface of the contact glass on which the manuscript is set; a carriage which is supported by the rail member to be slidable along the second direction and contains the image sensor in a sensor container having a recess open to a contact glass side, the carriage being supported to be swingable about the rail member at a central portion thereof in the first direction, and having a taper end portion (32, 33) which is formed in an end portion thereof in the first direction to be smaller in height toward an end side and an opening (34, 35) penetrating a bottom surface of the sensor container such that an end portion of the image sensor may project downward below the bottom surface of the carriage on a side of the taper end portion (32, 33); a biased portion which is provided adjacent to the reading surface of the image sensor in the second direction on the side of the taper end portion (32, 33); and a biasing member provided between the biased portion and the carriage to bias the image sensor toward the contact glass via the biased portion.