An object of the present invention is to provide a bolometer having a high TCR value and a low resistance, and a method for manufacturing the infrared sensor. One aspect of the present embodiment relates to a bolometer comprising: a substrate; a first electrode on the substrate; a second electrode spaced from the first electrode on the substrate; and a carbon nanotube layer electrically connected to the first electrode and the second electrode, wherein the carbon nanotube layer comprises 90% by mass or more of semiconducting carbon nanotubes based on the total amount of carbon nanotubes, and the carbon nanotube layer has an alignment satisfying: fx/fy≥2 where an integrated value f of amplitudes of frequencies from −1 μm−1 to +1 μm−1 in one direction from the center is calculated in an image obtained by performing two-dimensional fast Fourier transform processing on an SEM image of the carbon nanotube layer, and an integrated value for a direction x in which the integrated value f becomes maximum is defined as fx and an integrated value for a direction y perpendicular to the direction x is defined as fy.