A card reader, comprising: an insertion port into which a card incorporating an IC chip is inserted; a metal detection mechanism structured to detect an external connection terminal of the IC chip provided in the card; and a tip end detection mechanism structured to detect a tip end in an inserting direction of the card inserted into the insertion port; wherein the metal detection mechanism and the tip end detection mechanism are disposed so that, when the card is inserted into the insertion port in a correct posture, the tip end detection mechanism detects the tip end of the card and the metal detection mechanism detects the external connection terminal, the card reader being characterized in that the card is formed in a substantially rectangular shape and is taken into the insertion port in a short widthwise direction of the card and is processed; and in that the card reader further comprises: a width detection mechanism structured to detect both end parts of the card in a width direction which is perpendicular to a thickness direction and the inserting direction of the card inserted into the insertion port; and a control section into which an output signal of the metal detection mechanism, an output signal of the tip end detection mechanism and an output signal of the width detection mechanism are inputted, wherein the width detection mechanism is disposed on an insertion port side relative to the tip end detection mechanism, and wherein the control section determines whether the card has been inserted into the insertion port in a correct posture or not based on a difference between a signal level of an output signal of the metal detection mechanism when the width detection mechanism detects both end parts of the card and a signal level of an output signal of the metal detection mechanism when the tip end detection mechanism detects a tip end of the card in the inserting direction. an insertion port into which a card incorporating an IC chip is inserted; a metal detection mechanism structured to detect an external connection terminal of the IC chip provided in the card; and a tip end detection mechanism structured to detect a tip end in an inserting direction of the card inserted into the insertion port; wherein the metal detection mechanism and the tip end detection mechanism are disposed so that, when the card is inserted into the insertion port in a correct posture, the tip end detection mechanism detects the tip end of the card and the metal detection mechanism detects the external connection terminal, the card reader being characterized in that the card is formed in a substantially rectangular shape and is taken into the insertion port in a short widthwise direction of the card and is processed; and in that the card reader further comprises: a width detection mechanism structured to detect both end parts of the card in a width direction which is perpendicular to a thickness direction and the inserting direction of the card inserted into the insertion port; and a control section into which an output signal of the metal detection mechanism, an output signal of the tip end detection mechanism and an output signal of the width detection mechanism are inputted, wherein the width detection mechanism is disposed on an insertion port side relative to the tip end detection mechanism, and wherein the control section determines whether the card has been inserted into the insertion port in a correct posture or not based on a difference between a signal level of an output signal of the metal detection mechanism when the width detection mechanism detects both end parts of the card and a signal level of an output signal of the metal detection mechanism when the tip end detection mechanism detects a tip end of the card in the inserting direction. a width detection mechanism structured to detect both end parts of the card in a width direction which is perpendicular to a thickness direction and the inserting direction of the card inserted into the insertion port; and a control section into which an output signal of the metal detection mechanism, an output signal of the tip end detection mechanism and an output signal of the width detection mechanism are inputted, wherein the width detection mechanism is disposed on an insertion port side relative to the tip end detection mechanism, and wherein the control section determines whether the card has been inserted into the insertion port in a correct posture or not based on a difference between a signal level of an output signal of the metal detection mechanism when the width detection mechanism detects both end parts of the card and a signal level of an output signal of the metal detection mechanism when the tip end detection mechanism detects a tip end of the card in the inserting direction.