An engine control device comprising a multi-core processor in which a plurality of cores are arranged in a lattice shape, and that calculates a control target value of one or a plurality of actuators using the multi-core processor, comprising: a plurality of lattice points that are arranged in a three-dimensional Cartesian coordinate system that takes a first operating condition, a second operating condition and a third operating condition as axes are associated in a one-to-one relationship with at least some of the plurality of cores, and a calculation program for calculating the control target value of the one or plurality of actuators at the associated lattice points is allocated to the at least some of the plurality of cores; wherein each core with which a lattice point is associated is programmed so that, when an operating space in the three-dimensional Cartesian coordinate system to which a current operating point belongs is defined by eight adjacent lattice points that include a lattice point associated with a core, the associated core calculates a first control value at the lattice point by means of the calculation program and sends the first control value to an interpolation calculation core, and when the operating space is not defined by eight adjacent lattice points that include a lattice point associated with the core, the core suspends calculation of the first control value at the lattice point; and wherein the interpolation calculation core is programmed to perform an interpolation calculation to calculate a second control value at the operating point using the first control values calculated at eight adjacent lattice points defining the operating space corresponding to the operating point; and wherein the multi-core processor outputs the second control value at the operating point that is obtained by the interpolation calculation as the control target value, and wherein: a plurality of core groups comprising four adjacent cores are set; four consecutive lattice points at which respective coordinates of the first and second operating conditions are identical and coordinates of the third operating condition are different are associated with the respective core groups; and the respective core groups are arranged in an identical order as lattice points in a two-dimensional Cartesian coordinate system that takes the first operating condition and the second operating condition as axes, and wherein the multi-core processor interchanges lattice points that the respective cores are responsible for in sequential order within the core group. a plurality of lattice points that are arranged in a three-dimensional Cartesian coordinate system that takes a first operating condition, a second operating condition and a third operating condition as axes are associated in a one-to-one relationship with at least some of the plurality of cores, and a calculation program for calculating the control target value of the one or plurality of actuators at the associated lattice points is allocated to the at least some of the plurality of cores; wherein each core with which a lattice point is associated is programmed so that, when an operating space in the three-dimensional Cartesian coordinate system to which a current operating point belongs is defined by eight adjacent lattice points that include a lattice point associated with a core, the associated core calculates a first control value at the lattice point by means of the calculation program and sends the first control value to an interpolation calculation core, and when the operating space is not defined by eight adjacent lattice points that include a lattice point associated with the core, the core suspends calculation of the first control value at the lattice point; and wherein the interpolation calculation core is programmed to perform an interpolation calculation to calculate a second control value at the operating point using the first control values calculated at eight adjacent lattice points defining the operating space corresponding to the operating point; and wherein the multi-core processor outputs the second control value at the operating point that is obtained by the interpolation calculation as the control target value, and wherein: a plurality of core groups comprising four adjacent cores are set; four consecutive lattice points at which respective coordinates of the first and second operating conditions are identical and coordinates of the third operating condition are different are associated with the respective core groups; and the respective core groups are arranged in an identical order as lattice points in a two-dimensional Cartesian coordinate system that takes the first operating condition and the second operating condition as axes, and wherein the multi-core processor interchanges lattice points that the respective cores are responsible for in sequential order within the core group. a plurality of core groups comprising four adjacent cores are set; four consecutive lattice points at which respective coordinates of the first and second operating conditions are identical and coordinates of the third operating condition are different are associated with the respective core groups; and the respective core groups are arranged in an identical order as lattice points in a two-dimensional Cartesian coordinate system that takes the first operating condition and the second operating condition as axes, and wherein the multi-core processor interchanges lattice points that the respective cores are responsible for in sequential order within the core group.