Object disappears when zoom

I have a great problem: i inserted an object in my scene, and i can see it in the Scene Tab, but when i play the game, it doesnt appears on the camera. but if i move away the camera, the object appears; i bring the camera closer and the object disappears again, like this:

as you can see, in the first image the object is in the game but far away. in the second one, the object isn't there, you can see the main camera's poition, i moved it just a little. please help.