A transmission apparatus: encodes information into a first bit sequence, using a polar code; outputs a second bit sequence by inputting the first bit sequence to an interleaver; modulates the second bit sequence into modulation symbols according to a modulation order; and transmits the modulation symbols. The interleaver: has an odd number of columns; and is configured to cyclically read and output, from column k, bits stored in row n of the interleaver, and cyclically read and output, from column k+a, bits stored in row n+1 of the interleaver, wherein a represents an integer which is not 0.