An internal combustion engine control device comprising: a learning map (100, 110, 120, 124, 130, 134, 138, 142, 142', 150, 150', 160, 170, 180, 192, 200, 210, 222, 230, 240) having a plurality of grid points and storing a learning value of a control parameter used for control of an internal combustion engine at each of the grid points, wherein the learning value is capable of being updated and is calculated based on a reference parameter corresponding to an axis of the learning map; weight setting means for setting a weight of each grid point of the learning map (100, 110, 120, 124, 130, 134, 138, 142, 142', 150, 150', 160, 170, 180, 192, 200, 210, 222, 230, 240) when a value of the control parameter is acquired and for decreasing the weight of the grid point as a distance from a reference position to the grid point becomes larger, wherein the reference position is a position, on the learning map, of the reference parameter at which the value of the control parameter is acquired; weighting learning means for executing weighting learning control for updating, each time the value of the control parameter is acquired, the learning value of the respective grid points so that the larger the weight is, the more the acquired value of the control parameter is reflected in the learning value at all the grid points; characterized by further comprising a reliability map having a plurality of grid points configured similarly to the learning map (100, 110, 120, 124, 130, 134, 138, 142, 142', 150, 150', 160, 170, 180, 192, 200, 210, 222, 230, 240) and storing a reliability evaluation value which is an index indicating reliability of the learning value at each of the grid points, capable of being updated; reliability map weight setting means for decreasing a reliability weight which is a weight of each grid point of the reliability map as the distance from the reference position to the grid point becomes larger and in which the decrease characteristic of the reliability weight is set steeper than the decrease characteristic of the weight of the learning map (100, 110, 120, 124, 130, 134, 138, 142, 142', 150, 150', 160, 170, 180, 192, 200, 210, 222, 230, 240); and reliability map learning means for setting, to the reference position, a reliability acquired value having a value corresponding to reliability of the acquired value of the control parameter, and for updating the reliability evaluation value of the respective grid points so that, the larger the reliability weight is, the more the reliability acquired value is reflected in the reliability evaluation value at all the grid points of the reliability map. a learning map (100, 110, 120, 124, 130, 134, 138, 142, 142', 150, 150', 160, 170, 180, 192, 200, 210, 222, 230, 240) having a plurality of grid points and storing a learning value of a control parameter used for control of an internal combustion engine at each of the grid points, wherein the learning value is capable of being updated and is calculated based on a reference parameter corresponding to an axis of the learning map; weight setting means for setting a weight of each grid point of the learning map (100, 110, 120, 124, 130, 134, 138, 142, 142', 150, 150', 160, 170, 180, 192, 200, 210, 222, 230, 240) when a value of the control parameter is acquired and for decreasing the weight of the grid point as a distance from a reference position to the grid point becomes larger, wherein the reference position is a position, on the learning map, of the reference parameter at which the value of the control parameter is acquired; weighting learning means for executing weighting learning control for updating, each time the value of the control parameter is acquired, the learning value of the respective grid points so that the larger the weight is, the more the acquired value of the control parameter is reflected in the learning value at all the grid points; characterized by further comprising a reliability map having a plurality of grid points configured similarly to the learning map (100, 110, 120, 124, 130, 134, 138, 142, 142', 150, 150', 160, 170, 180, 192, 200, 210, 222, 230, 240) and storing a reliability evaluation value which is an index indicating reliability of the learning value at each of the grid points, capable of being updated; reliability map weight setting means for decreasing a reliability weight which is a weight of each grid point of the reliability map as the distance from the reference position to the grid point becomes larger and in which the decrease characteristic of the reliability weight is set steeper than the decrease characteristic of the weight of the learning map (100, 110, 120, 124, 130, 134, 138, 142, 142', 150, 150', 160, 170, 180, 192, 200, 210, 222, 230, 240); and reliability map learning means for setting, to the reference position, a reliability acquired value having a value corresponding to reliability of the acquired value of the control parameter, and for updating the reliability evaluation value of the respective grid points so that, the larger the reliability weight is, the more the reliability acquired value is reflected in the reliability evaluation value at all the grid points of the reliability map.