A tool management device, comprising: an accumulated wear amount calculation section configured to calculate a wear amount of a blade edge of a punch and a wear amount of a blade edge of a die when a tool set of the punch and the die has processed a sheet metal once, and to calculate an accumulated wear amount of the blade edge of the punch and an accumulated wear amount of the blade edge of the die by accumulating wear amounts of respective times when the tool set has processed the sheet metal multiple times; and a tool management information managing section configured to manage a state of the blade edge of each punch and each die by causing a tool management information storage section to store tool management information associating a tool identification code given to each punch and each die with the accumulated wear amounts calculated by the accumulated wear amount calculation section, characterized in that the accumulated wear amount calculation section is configured: to calculate the wear amount of the blade edge of the punch and the wear amount of the blade edge of the die when the tool set of the punch and the die has processed the sheet metal once, by an arithmetic equation using coefficients corresponding to a clearance value between dimensions of the blade edge of the punch and dimensions of the blade edge of the die when the punching machine has processed the sheet metal with the tool set, and to calculate the wear amounts by using a first coefficient, a second coefficient, or a third coefficient different from each other, when the clearance value of the tool set is larger than a recommended clearance, within a range of the recommended clearance, or smaller than the recommended clearance, respectively. an accumulated wear amount calculation section configured to calculate a wear amount of a blade edge of a punch and a wear amount of a blade edge of a die when a tool set of the punch and the die has processed a sheet metal once, and to calculate an accumulated wear amount of the blade edge of the punch and an accumulated wear amount of the blade edge of the die by accumulating wear amounts of respective times when the tool set has processed the sheet metal multiple times; and a tool management information managing section configured to manage a state of the blade edge of each punch and each die by causing a tool management information storage section to store tool management information associating a tool identification code given to each punch and each die with the accumulated wear amounts calculated by the accumulated wear amount calculation section, to calculate the wear amount of the blade edge of the punch and the wear amount of the blade edge of the die when the tool set of the punch and the die has processed the sheet metal once, by an arithmetic equation using coefficients corresponding to a clearance value between dimensions of the blade edge of the punch and dimensions of the blade edge of the die when the punching machine has processed the sheet metal with the tool set, and to calculate the wear amounts by using a first coefficient, a second coefficient, or a third coefficient different from each other, when the clearance value of the tool set is larger than a recommended clearance, within a range of the recommended clearance, or smaller than the recommended clearance, respectively.