Is it possible to reproduce Double-slit experiment by myself at home? I want to reproduce this experiment by myself. What I need for this. What parameters of slits and laser/another light source it needs? Is it possible to make DIY-detector?
 A: Absolutely, though the result does depend somewhat upon your definition of "at home".
Simply seeing the interference pattern is as simple as a laser pointer and a few narrow apertures (see the other answer(s))
People have successfully even done single-photon interference at home!
A: It's actually quite easy to perform the experiment in the comfort of your own home.  The simplest setup I have seen (as depicted in this, and other youtube videos) is to use a laser pointer and pencil lead, but you can certainly be more systematic and cut slits in some opaque material as well.
I would encourage you to experiment to answer the question of how far apart the slits need to be etc., but some basic math behind this is as follows:  If the slits are a distance $d$ apart, if the light has wavelength $\lambda$, and if the distance between the slits and the screen is $L$, then the spacing $\Delta y$ between successive fringes on the wall will approximately be
$$
  \Delta y \approx \frac{\lambda L}{d}
$$
So let's say the laser is red so that $\lambda\approx 700 \mathrm{nm}$,  the slits are $1\,\mathrm{mm}$ apart, and the screen is $1.5\,\mathrm m$ away from the slits, then we have
$$
  \Delta y \approx \frac{(700\,\mathrm{nm})(1.5\,\mathrm{m})}{1\,\mathrm{mm}} = 1.05\,\mathrm{mm}
$$
So you can actually try this and see if your results agree! (I might actually try this myself come to think of it; thanks for the question!)
Cheers!
A: Laser pointer, nit comb, bit of cardboard from a cereal box to control the number of slits. Works perfectly!
