Touched position detection method for touch panel

A touched position detection method for a touch panel for detecting a touched position, based on current measured values by sensors and reference values which are measured values by sensors with absence of a touch, comprising:

• a step of selecting sensors located in a vicinity of a sensor showing a measured value higher than a predetermined level, wherein content of an update process for updating the reference values is controlled depending on whether or not sensors of concern are included in the selected sensors and,
• a step of applying a first noise reduction parameter to measured values by the selected sensors and applying a second noise reduction parameter which is different from the first noise reduction parameter to measured values by other sensors having a measured value lower than the measured value of the selected sensors,
• wherein the first and second noise reduction parameters are respectively predetermined values to be subtracted from a measured value by a sensor to be referred to in a touched position calculation process.