Infusion device , particularly for machines for preparing an infusion beverage with a capsule containing an aromatic substance, comprising: - a first infusing member , - a second infusing member adapted for cooperating with said first infusing member ; said second infusing member comprising a housing seat for a capsule-holder or a pod-holder; - said capsule-holder or pod-holder comprising a recess for at least partially accommodating an infusion capsule ; - said capsule-holder or pod-holder being removably introducible in said housing seat ; - said second infusing member being hinged to said first infusing member along a hinge axis (X-X) to rotate with respect to said first infusing member between a closed position, in which said second infusing member closes said first infusing member to define a capsule-holder or pod-holder inserted in said housing seat , an infusion chamber and a rotated open position in which said second infusing member is partially spaced from the first infusing member of a distance allowing the capsule-holder or pod-holder to be drawn out; - said second infusing member being hinged to said first infusing member so that the hinge axis (X-X) is free to pitch; characterised that it comprises - activating means adapted to activate the second infusing member for the rotation movement from the open position to the closed position, and vice versa; - said activating means comprise at least one pivot member and at least one curvilinear profile , - said pivot member takes the form of a manually operable lever operatively hinged to the first infusing member so that the rotation of said lever in a way entails the rotation of said at least one pivot member with respect to said curvilinear profile integral to said second infusing member and , consequently, the movement of the second infusing member from said open position to said closed position; - said at least one curvilinear profile is made so that its convexity faces said at least one pivot member . - a first infusing member , - a second infusing member adapted for cooperating with said first infusing member ; said second infusing member comprising a housing seat for a capsule-holder or a pod-holder; - said capsule-holder or pod-holder comprising a recess for at least partially accommodating an infusion capsule ; - said capsule-holder or pod-holder being removably introducible in said housing seat ; - said second infusing member being hinged to said first infusing member along a hinge axis (X-X) to rotate with respect to said first infusing member between a closed position, in which said second infusing member closes said first infusing member to define a capsule-holder or pod-holder inserted in said housing seat , an infusion chamber and a rotated open position in which said second infusing member is partially spaced from the first infusing member of a distance allowing the capsule-holder or pod-holder to be drawn out; - said second infusing member being hinged to said first infusing member so that the hinge axis (X-X) is free to pitch; - activating means adapted to activate the second infusing member for the rotation movement from the open position to the closed position, and vice versa; - said activating means comprise at least one pivot member and at least one curvilinear profile , - said pivot member takes the form of a manually operable lever operatively hinged to the first infusing member so that the rotation of said lever in a way entails the rotation of said at least one pivot member with respect to said curvilinear profile integral to said second infusing member and , consequently, the movement of the second infusing member from said open position to said closed position; - said at least one curvilinear profile is made so that its convexity faces said at least one pivot member . <EOS>