Emerged during and after the return from Babylonian exile. It contains mostly cultic (levitical) clauses. As the 3rd book of Moses, it was begotten in the then available form. The whole book is analytically divided in 7 parts:
1st part: Sacrificial dictates for the people
2nd part: Sacrificial dictates for the priests
3rd part: Priest Act
4th part: Purity Law
5th part: Ritual for the Day of Atonement
6th part: Holiness Code
a. Crimes punishable by death
b. Rules for priests
c. Further sacrificial dictates
d. Ordinances and ceremonial dictates
e. Sabbatical and jubilee
f. Resolution of vows and votive offerings

P.S.
I have rendered the numbers of the chapters neutrally. They should really have no influence on the content.