Shape measuring device and computer-readable memory medium

A shape measuring device, comprising:

• a coordinate value calculation unit that acquires a height of a surface of a measurement object from a distance sensor that moves relative to the surface of the measurement object, and calculates coordinate values of a rising edge or falling edge existing on the surface of the measurement object based on the height;
• a reference value storage unit that stores reference values of the coordinate values of the rising edge or falling edge;
• a data comparison unit that compares the reference values with coordinate values calculated by the coordinate value calculation unit;
• and
• a factor determination unit that determines coordinate values that are different from the reference values as incorrect data, changes a speed condition of a relative seed between the measurement object and the distance sensor, and makes a comparison of coordinate values calculated on a different speed condition to thereby determine a factor causing the incorrect data.