[en] This is intended to be a pedagogical review of scalar field propagator on adS space in view of adS/CFT correspondence. There no new results but instead it gathers ideas from the literature and present them in a consistent way, with insights on some difficult points. Contents: 1 - Equations of motion; 2 - Solutions (Separation of variables and solution in x-direction; Solution for the radial direction (k2 > 0) and scaling; Solution for the radial direction (k2 < 0) and scaling; Asymptotic behavior and boundary field (k2 > 0); Complete (free) solution; 3 - Another quantization scheme; 4 - Bulk-to-bulk propagator (General properties, Explicit form); 5 - Boundary-to-bulk propagator (Link to the bulk-to-bulk propagator; General expression; Witten's method); 6 - Boundary-to-boundary propagator; 7 - Full solution from Witten's Green function; 8 - Witten's diagrams; 9 - Evaluation of the action (Position space: Witten's Green function; Momentum space: Green function ('Freedman's' method); Momentum space: Green function (alternative method)); 10 - Cubic interactions; 11 - Comments; 12 - Appendixes (Conventions, Anti de Sitter space, AdS/CFT correspondence, Special functions).