An in-vehicle device comprising: a first speech recognition unit configured to recognize a word indicating the in-vehicle device and a word indicating a first instruction type by speech recognition, from first voice data input to the in-vehicle device, the first instruction type being one of instruction types for operating the in-vehicle device; and a second speech recognition unit configured, in response to the word indicating the in-vehicle device being recognized from the first voice data by the first speech recognition unit, to recognize a word indicating a second instruction type by speech recognition, from second voice data input to the in-vehicle device, the second voice data being input after the first voice data, and the second instruction type being one of the instruction types for operating the in-vehicle device, wherein the first speech recognition unit is capable of recognizing the word indicating the first instruction type, regardless of whether or not the word indicating the in-vehicle device is recognized from the first voice data by the first speech recognition unit; and a storage unit configured to store the word indicating the in-vehicle device and the word indicating the first instruction type, wherein the first speech recognition unit is configured to perform speech recognition by retrieving a word stored in the storage unit and by determining whether or not the first voice data matches the word that is retrieved from the storage unit, characterised in that in response to determination that a speaking frequency calculated based on third voice data input to the in-vehicle device is equal to or greater than a predetermined threshold, the first speech recognition unit is further configured to: retrieve the word indicating the in-vehicle device from the storage unit, and determine whether or not fourth voice data that is input after the third voice data matches the word indicating the in-vehicle device that is retrieved from the storage unit. a first speech recognition unit configured to recognize a word indicating the in-vehicle device and a word indicating a first instruction type by speech recognition, from first voice data input to the in-vehicle device, the first instruction type being one of instruction types for operating the in-vehicle device; and a second speech recognition unit configured, in response to the word indicating the in-vehicle device being recognized from the first voice data by the first speech recognition unit, to recognize a word indicating a second instruction type by speech recognition, from second voice data input to the in-vehicle device, the second voice data being input after the first voice data, and the second instruction type being one of the instruction types for operating the in-vehicle device, wherein the first speech recognition unit is capable of recognizing the word indicating the first instruction type, regardless of whether or not the word indicating the in-vehicle device is recognized from the first voice data by the first speech recognition unit; and a storage unit configured to store the word indicating the in-vehicle device and the word indicating the first instruction type, wherein the first speech recognition unit is configured to perform speech recognition by retrieving a word stored in the storage unit and by determining whether or not the first voice data matches the word that is retrieved from the storage unit, characterised in that in response to determination that a speaking frequency calculated based on third voice data input to the in-vehicle device is equal to or greater than a predetermined threshold, the first speech recognition unit is further configured to: retrieve the word indicating the in-vehicle device from the storage unit, and determine whether or not fourth voice data that is input after the third voice data matches the word indicating the in-vehicle device that is retrieved from the storage unit. retrieve the word indicating the in-vehicle device from the storage unit, and determine whether or not fourth voice data that is input after the third voice data matches the word indicating the in-vehicle device that is retrieved from the storage unit.