  The problem of finding a formulation of Noether's theorem in noncommutative
geometry is very important in order to obtain conserved currents and charges
for particles in noncommutative spacetimes. In this paper, we formulate
Noether's theorem for translations of kappa-Minkowski noncommutative spacetime
on the basis of the 5-dimensional kappa-Poincare' covariant differential
calculus. We focus our analysis on the simple case of free scalar theory. We
obtain five conserved Noether currents, which give rise to five energy-momentum
charges. By applying our result to plane waves it follows that the
energy-momentum charges satisfy a special-relativity dispersion relation with a
generalized mass given by the fifth charge. In this paper we provide also a
rigorous derivation of the equation of motion from Hamilton's principle in
noncommutative spacetime, which is necessary for the Noether analysis.
