To solve the problem of a conventional continuous form printer that the speed at which the end of a sheet passes through a sheet sensor depends on the print data and an error may occur in the residual quantity of a printable sheet depending on the data.

The printer comprises a means for setting an adjusting value of residual quantity of a printable sheet at the time of forward sheet feed, a means for setting the adjusting value of residual quantity of the printable sheet at the time of reverse sheet feed, a nonvolatile memory element, a means for storing the adjusting value of residual quantity of the printable sheet in the nonvolatile memory element, and a means for reading out the adjusting value of residual quantity of the printable sheet from the nonvolatile memory element.